.TH "gdal_utilities" 1 "Mon Apr 25 2016" "GDAL" \" -*- nroff -*-
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.SH NAME
gdal_utilities \- GDAL Utilities 
A collection of GDAL related programs\&.
.PP
The following utility programs are distributed with GDAL\&.
.PP
.PD 0
.IP "\(bu" 2
\fBgdalinfo\fP - report information about a file\&. 
.IP "\(bu" 2
\fBgdal_translate\fP - Copy a raster file, with control of output format\&. 
.IP "\(bu" 2
\fBgdaladdo\fP - Add overviews to a file\&. 
.IP "\(bu" 2
\fBgdalwarp\fP - Warp an image into a new coordinate system\&. 
.IP "\(bu" 2
\fBgdaltindex\fP - Build a MapServer raster tileindex\&. 
.IP "\(bu" 2
\fBgdalbuildvrt\fP - Build a VRT from a list of datasets\&. 
.IP "\(bu" 2
\fBgdal_contour\fP - Contours from DEM\&. 
.IP "\(bu" 2
\fBgdaldem\fP - Tools to analyze and visualize DEMs\&. 
.IP "\(bu" 2
\fBrgb2pct\&.py\fP - Convert a 24bit RGB image to 8bit paletted\&. 
.IP "\(bu" 2
\fBpct2rgb\&.py\fP - Convert an 8bit paletted image to 24bit RGB\&. 
.IP "\(bu" 2
\fBgdal_merge\&.py\fP - Build a quick mosaic from a set of images\&. 
.IP "\(bu" 2
\fBgdal2tiles\&.py\fP - Create a TMS tile structure, KML and simple web viewer\&. 
.IP "\(bu" 2
\fBgdal_rasterize\fP - Rasterize vectors into raster file\&. 
.IP "\(bu" 2
\fBgdaltransform\fP - Transform coordinates\&. 
.IP "\(bu" 2
\fBnearblack\fP - Convert nearly black/white borders to exact value\&. 
.IP "\(bu" 2
\fBgdal_retile\&.py\fP - Retiles a set of tiles and/or build tiled pyramid levels\&. 
.IP "\(bu" 2
\fBgdal_grid\fP - Create raster from the scattered data\&. 
.IP "\(bu" 2
\fBgdal_proximity\&.py\fP - Compute a raster proximity map\&. 
.IP "\(bu" 2
\fBgdal_polygonize\&.py\fP - Generate polygons from raster\&. 
.IP "\(bu" 2
\fBgdal_sieve\&.py\fP - Raster Sieve filter\&. 
.IP "\(bu" 2
\fBgdal_fillnodata\&.py\fP - Interpolate in nodata regions\&. 
.IP "\(bu" 2
\fBgdallocationinfo\fP - Query raster at a location\&. 
.IP "\(bu" 2
\fBgdalsrsinfo\fP - Report a given SRS in different formats\&. (GDAL >= 1\&.9\&.0) 
.IP "\(bu" 2
\fBgdalmove\&.py\fP - Transform the coordinate system of a file (GDAL >= 1\&.10) 
.IP "\(bu" 2
\fBgdal_edit\&.py\fP - Edit in place various information of an existing GDAL dataset (projection, geotransform, nodata, metadata) 
.IP "\(bu" 2
\fBgdal_calc\&.py\fP - Command line raster calculator with numpy syntax 
.IP "\(bu" 2
\fBgdal_pansharpen\&.py\fP - Perform a pansharpen operation\&. 
.IP "\(bu" 2
\fBgdal-config\fP - Get options required to build software using GDAL\&. 
.IP "\(bu" 2
\fBgdalmanage\fP - Identify, copy, rename and delete raster\&. 
.IP "\(bu" 2
\fBgdalcompare\&.py\fP - Compare two images and report on differences\&. 
.PP
.SH "Creating New Files"
.PP
Access an existing file to read it is generally quite simple\&. Just indicate the name of the file or dataset on the command line\&. However, creating a file is more complicated\&. It may be necessary to indicate the the format to create, various creation options affecting how it will be created and perhaps a coordinate system to be assigned\&. Many of these options are handled similarly by different GDAL utilities, and are introduced here\&. 
.PP
.IP "\fB\fB-of\fP \fIformat\fP\fP" 1c
Select the format to create the new file as\&. The formats are assigned short names such as GTiff (for GeoTIFF) or HFA (for Erdas Imagine)\&. The list of all format codes can be listed with the \fB--formats\fP switch\&. Only formats list as '(rw)' (read-write) can be written\&.
.PP
Many utilities default to creating GeoTIFF files if a format is not specified\&. File extensions are not used to guess output format, nor are extensions generally added by GDAL if not indicated in the filename by the user\&. 
.PP
.IP "\fB\fB-co\fP \fINAME=VALUE\fP\fP" 1c
Many formats have one or more optional creation options that can be used to control particulars about the file created\&. For instance, the GeoTIFF driver supports creation options to control compression, and whether the file should be tiled\&.
.PP
The creation options available vary by format driver, and some simple formats have no creation options at all\&. A list of options supported for a format can be listed with the '--format <format>' command line option but the web page for the format is the definitive source of information on driver creation options\&.
.PP
.PP
.IP "\fB\fB-a_srs\fP \fISRS\fP\fP" 1c
Several utilities, (gdal_translate and gdalwarp) include the ability to specify coordinate systems with command line options like \fB-a_srs\fP (assign SRS to output), \fB-s_srs\fP (source SRS) and \fB-t_srs\fP (target SRS)\&.
.PP
These utilities allow the coordinate system (SRS = spatial reference system) to be assigned in a variety of formats\&.
.PP
.PP
.PD 0
.IP "\(bu" 2
\fBNAD27\fP/\fBNAD83\fP/\fBWGS84\fP/\fBWGS72\fP: These common geographic (lat/long) coordinate systems can be used directly by these names\&.
.PP

.IP "\(bu" 2
\fBEPSG:\fP\fIn\fP: Coordinate systems (projected or geographic) can be selected based on their EPSG codes, for instance EPSG:27700 is the British National Grid\&. A list of EPSG coordinate systems can be found in the GDAL data files gcs\&.csv and pcs\&.csv\&.
.PP

.IP "\(bu" 2
\fIPROJ\&.4 Definitions\fP: A PROJ\&.4 definition string can be used as a coordinate system\&. For instance '+proj=utm +zone=11 +datum=WGS84'\&. Take care to keep the proj\&.4 string together as a single argument to the command (usually by double quoting)\&. 
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.IP "\(bu" 2
\fIOpenGIS Well Known Text\fP: The Open GIS Consortium has defined a textual format for describing coordinate systems as part of the Simple Features specifications\&. This format is the internal working format for coordinate systems used in GDAL\&. The name of a file containing a WKT coordinate system definition may be used a coordinate system argument, or the entire coordinate system itself may be used as a command line option (though escaping all the quotes in WKT is quite challenging)\&. 
.PP
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\fIESRI Well Known Text\fP: ESRI uses a slight variation on OGC WKT format in their ArcGIS product (ArcGIS \&.prj files), and these may be used in a similar manner to WKT files, but the filename should be prefixed with \fBESRI::\fP\&. For example \fB'ESRI::NAD 1927 StatePlane Wyoming West FIPS 4904\&.prj'\fP\&. 
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\fISpatial References from URLs\fP: For example http://spatialreference.org/ref/user/north-pacific-albers-conic-equal-area/\&.
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.IP "\(bu" 2
\fIfilename\fP: The name of a file containing WKT, PROJ\&.4 strings, or XML/GML coordinate system definitions can be provided\&. 
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.PP
.SH "General Command Line Switches"
.PP
All GDAL command line utility programs support the following 'general' options\&.
.PP
.IP "\fB\fB--version\fP\fP" 1c
Report the version of GDAL and exit\&.
.PP
.IP "\fB\fB--formats\fP\fP" 1c
List all raster formats supported by this GDAL build (read-only and read-write) and exit\&. The format support is indicated as follows: 'ro' is read-only driver; 'rw' is read or write (i\&.e\&. supports CreateCopy); 'rw+' is read, write and update (i\&.e\&. supports Create)\&. A 'v' is appended for formats supporting virtual IO (/vsimem, /vsigzip, /vsizip, etc)\&. A 's' is appended for formats supporting subdatasets\&. Note: The valid formats for the output of gdalwarp are formats that support the Create() method (marked as rw+), not just the CreateCopy() method\&. 
.PP
.IP "\fB\fB--format\fP \fIformat\fP\fP" 1c
List detailed information about a single format driver\&. The \fIformat\fP should be the short name reported in the \fB--formats\fP list, such as GTiff\&.
.PP
.IP "\fB\fB--optfile\fP \fIfile\fP\fP" 1c
Read the named file and substitute the contents into the command line options list\&. Lines beginning with # will be ignored\&. Multi-word arguments may be kept together with double quotes\&. 
.PP
.IP "\fB\fB--config\fP \fIkey value\fP\fP" 1c
Sets the named \fCconfiguration keyword\fP to the given value, as opposed to setting them as environment variables\&. Some common configuration keywords are GDAL_CACHEMAX (memory used internally for caching in megabytes) and GDAL_DATA (path of the GDAL 'data' directory)\&. Individual drivers may be influenced by other configuration options\&. 
.PP
.IP "\fB\fB--debug\fP \fIvalue\fP\fP" 1c
Control what debugging messages are emitted\&. A value of \fION\fP will enable all debug messages\&. A value of \fIOFF\fP will disable all debug messages\&. Another value will select only debug messages containing that string in the debug prefix code\&. 
.PP
.IP "\fB\fB--help-general\fP\fP" 1c
Gives a brief usage message for the generic GDAL command line options and exit\&. 
.PP
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.PP
 
